The simple answer is: quality of the code. While we were in incubation mode, we felt it was OK to put out code that wasn't well tested, because the aim was to get feedback, not to provide something that could be used for production code. With the CodePlex release,
however, we want to put out only code we can be proud of and stand by.

Thus, we pulled the server-side features out, along with the TCP support in the first release. It will come back in later releases, though, when we feel that it has received enough testing.